Polyamines (PA) have been implicated in a wide variety of fundamental cellular processes both in normal and in neoplastic cells, but the nature of PA involvement is unclear. The long-range goal of this research is to develop the understanding of the roles of PA in cells, in particular by taking advantage of the genetic and physiological approaches available with Escherichia coli. The factors which lead to PA-dependence in certain strains of E. coli will be examined in three ways: a) the PA-requiring strain HT414 will be analyzed for all non-wild type alleles which contribute to the PA-dependent phenotype, b) PA-independent revertants of HT414 will be analyzed to identify at least four different types of suppressor mutations in different regions of the chromosome, which can lead to suppression of the PA requirement and c) newly identified basic compounds found in some of the revertants will be identified and tested for ability to fill the PA requirement of strain HT414. In addition, the genes identified in HT414 and various revertants will be analyzed for gene function either by comparison with known genes which map near the supressor mutations, or by cloning any newly identified suppressor genes onto plasmids, and identifying the products from the plasmids. From this work the identification of involvement of two types of cellular functions can be anticipated: functions involved in synthesis or modification of PA or PA-like compounds, and functions which require PA or related compounds for activity.